I think it needs more money ploughed into air fire assets on a national scale so they can be used right around a country as big as Australia. It is sadly a very unique geographical location, and international helpers could only be effective for a short period of time against this massive task.
Even if the whole AustralianArmy was mobilised it couldn't train them up for safety etc quick enough to be useful. I do think there needs to be a national aviation response like they have in Spain.
There fire dumping aircraft have been going for years but still extuinquish their blazes, but of course nothing like the Aussie bush fires!